Anytime people talk about "pain clinic" this issue keeps coming up. For a reason, unbeknownst to me, patients are expected to submit themselves to needling. Often these injections are performed weekly yet providing either no or very short-term pain relief. For the sake of argument, a placebo effect will not be discussed here, although, indeed there is a lot to do with the so-called expectations and other behavioural effects.
Physiologically, injected local anesthetics (hopefully, without corticosteroids) produce some pleasant warming numbness and muscle relaxation. Rarely, they offer long-lasting pain relief, but the mechanism is not clear. We can speculate that when these drugs are injected very close to the target nerve, or into the nerve, they cause neurotoxicity (poisoning) and slowing conduction of electric impulses through this nerve. There is another hypothesis of a so-called "pain reset," some magical Microsoft-like solution: if something doesn't work, and you don't know what to do, just click "restart." There is also a strong belief that with repeated nerve blocks, the pain will be diminishing. All these hypotheses have never been experimentally confirmed. On the other hand, tissue toxicity was documented in laboratory studies, and conscientious, ethical pain physicians published their experience disproving nerve injections (Arne Johansson and Bengt Sjolund. J Pain Symptom Manage 1996).
Thus, nerve blocks are rarely effective, their scientific level of evidence is undetermined, but sure enough, there is an ugly there. There is an inconvenient truth related to a fee for services system where doctors are paid per injection. Because, a single injection is not paid well, they do 6-12 needle punctures, injecting various unrelated and not united by sound diagnosis anatomical structures. I hope some doctors do this because they believe in this ritual. They were educated by older and imminent needle jockeys and genuinely considered "drill-mill" to be an equivalent of Pain Medicine. Maybe they are just blessed with ignorance? Otherwise, it must be greed. I refuse to believe they apply "My Mom's Principle" but instead shovelling a fundamental principle, "Do No Harm" into the deepest drawer. The excuse is always the same: "it is common practice, and everyone is doing it." This is true, but is it right?
Surprisingly, the regulations are very forgiving, and in the absence of evidence against this, multiple no sense injections are considered the standard of care. All that is needed is to obtain a permit specifically allowing clinics to implement these injections in their practice. Interestingly, no special permission is required for other procedures, such as joint aspirations. Perhaps, if someone comes with a swollen knee, offering injection in the neck, elbow and shoulder would be odd. However, when the low back hurts, no one asks why 10-12 injections are being performed including remote nerve blocks.
We always say our Canadian system is not ideal, but at least we don't do unnecessary treatments as Americans do. Well, in this case, our system is much worse. Certainly, some American doctors may also turn patients into pincushions to fill their bank accounts. However, the practice of multiple frequent injections is discouraged. There have been cases when doctors ended up in jail for Medicare fraud. The American Society of Anesthesiologists recommended against nerve blocks for chronic pain other than for diagnostic purposes a long time ago. In the absence of a similar position here, when nonsense declared as appropriate and medically necessary, and authorities turn a blind eye, patients must be vigilant and critical.